The present disclosure relates to a method of stabilizing catalase enzymes for longer term storage and stability until use. This disclosure also relates to the stabilized enzymes.
Oxygen is essential to sustaining life. Marine life utilize oxygen in dissolved form whereas land based species including humans utilize gaseous oxygen. The lack of oxygen or hypoxia is commonly experienced by people in their extremities (e.g. feet) as they get older due to poor blood circulation as well as by those with conditions such as diabetes. Studies have also shown below normal, low oxygen tension in the skins of older people. This often leads to poor skin health and an excessive presence of visible conditions such as wrinkles, dryness and lower skin elasticity. Over the years, cosmetic manufacturers have introduced skin formulations with a large variety of ingredients such as emollients, exfoliators, moisturizers etc., to retard these age related effects and improve and maintain skin health. Few formulations have focused on the direct delivery of oxygen to the skin.
Oxygen delivery to the skin has been examined for medical use, e.g. in treating of the compromised skin (wounds, inflammation and trauma) and more recently, intact skin. For example, Ladizinsky patented an oxygen generating wound dressing (U.S. Pat. No. 5,792,090). More recently, Gibbins et al. patented a method of making an oxygen generating foam dressing based on a polyacrylate polymer (U.S. Pat. No. 7,160,553). While the method of making an oxygen generating foam dressing is straightforward, the dressing itself suffers from a few drawbacks. For instance, the shelf life of the dressing is insufficient because oxygen from the dressing diffuses out of the foam cells over time. An alternative to the foam dressing in the form of an on-demand oxygen generating topical composition was proposed to overcome the limitation of the short shelf life (Ladizinsky US2009/0074880). In the '880 publication, a gel containing a catalyst and a peroxide in a separate reservoir, are brought together immediately before applying the mixture to the skin and covering it to maintain contact with the skin. Whether used for cosmetic applications or medical applications, oxygen generation is generally achieved though the catalytic decomposition of a peroxide, commonly hydrogen peroxide.
In any of the applications using catalyst and peroxide, a problem that has been found is that the catalyst can become inactivated during storage in a short period of time. Elevated temperatures accelerate this inactivation for many catalysts. For modern shipping and customer usage, it is important that the product be stable for a period of time sufficient to package, ship, market and sell it and to be stable in the user's home or other location. The stabilization of peroxide and/or a catalyst in a composition would be a step forward that would allow long term storage of the product. It would also be desirable if the product were stable at elevated temperatures commonly found in the shipping industry.
There is a need for a way of stabilizing a catalyst and/or peroxide for extended periods of time and at elevated temperatures. This would allow for the production, packaging, storage and shipping of a product without the product becoming deactivated before the customer was able to use it.